The present invention relates to a snap action type electric switch apparatus which is interposed, for instance, in a stop lamp circuit in an automobile or other conveyance.
As for an apparatus of this kind, such an arrangement has been heretofore known, in the form of a contact plate having a movable contact facing a stationary contact. It is provided in a machine housing so it is free to advance and retreat, with the contact plate connected through an intermediate such as a spring to a switching rod which extends from the back thereof and is arranged to be free to advance and retreat. With this conventional arrangement, however, in the course of such an opening operation wherein by an advance movement of the rod the two contacts are opened one from another while the spring is turned over, there is brought about a lowering in contact pressure between the two contacts immediately before the turnover movement. This results in such inconvenience that the contact between the two contact elements is made unstable. This may cause flickering of a lamp when the switch apparatus is used, for instance, in a lamp circuit, and it may also cause such an unstable condition that one of two circuits is opened while the other is closed when the switch is, for instance, of a three contact type and is used for simultaneous opening and closing of two circuits.
Accordingly, it is an object of the present invention to provide a snap action type of electric switch which avoids the aforementioned disadvantage.
Another object of the present invention is to provide a snap action type of switch which is substantially simple in construction and may be economically fabricated.
A further object of the present invention is to provide a snap action type of electric switch, as described, which may be readily maintained in service, and have a substantially long operating life.